1. Field of Invention
This invention relates to beverage forming machines, such as beverage brewing machines that form a beverage using a cartridge.
2. Related Art
Beverage forming machines commonly include a water supply, such as a storage tank or plumbed connection to a municipal source. Particularly for machines having a storage tank, a pump or other device is often needed to deliver water from the storage tank to various parts of the machine, such as a brew chamber where the water is mixed with a beverage medium to form a beverage.
Some coffee brewers made by Keurig, Incorporated of Reading, Mass. include a solenoid-operated pump to deliver water from a storage tank to a metering chamber where the water is heated. The solenoid-operated pumps include one or more check valves or other backflow preventer that prevents water from flowing in reverse direction from the metering tank to the storage tank.